Casing head



Aug. 14, 1928.

J. W. MCQUAID GASING HEAD Filed Aug. 9, 1926 Patented Aug. 14, 1928.

UNITED STATES JOHN W. MUQUAID, 0F FILLMORE, CALIFORNIA.

CASING HEAD.

Application led August 9, 1926. Serial No. 128,234.

This invention relates to well casing heads, of the eneral character commonly used in the drilling of oil wells and the like.

Among the principal objects of my invention are, the provision of a easlng head which is simple in construction, inexpensive to manufacture, and which conduces to easy and quick setting and eliicient sealing.

It is also an important feature of my invention to provide t. casing head adapted for easy and quick interchangeability of parts or the several diiierent fittings necessary for guiding and supporting the tubing within the casing durmg the drilling operations.

The details of construction and use of my improved casing head is more fully set forth in the following specification, reference being made therein to the accompanying drawings, forming a part hereof, and 1n which I have illustrated my preferred specilic embodiment; the right, of course, being ,reserved to make such changes and modiiications in structure as will properly come within the scope of the appended claim.

In these drawings:

Fig. 1 is a transverse vertical section taken through my casing head, showing it in assembled form ready for use;

Fig. 2 is a top plan view thereon taken as indicated by the line 2-2 of Fig. 1;

Fig. 3 is a vlew similar to Fig. 1, showing its use with a tubing guide block; and

Fig. 4 is a similar view illustrating the use of slips, in combination with an elevator, when lowering the tubing into the well.

Referring now to the drawings the numeral 10 designates generally the main or body portion of the head. This will preferably be made cylindrical and adapted for screw threaded connection upon the upper end of av well casing 11, so it is stpported a short distance above the ground or the iioor of the rig, as is customary in well construction.

While I have stated that the head member 10 is preferably cylindrical, it is, of course, understood that it may be made in any other cross sectional configuration suitable for the purpose, so long as the salient features of my invention are embodied therein.

The inner bore 12 of the lower neck portion 13 will preferably be substantially that of the casing 11, to provide adequate space for getting into and out of the casing, while the bore 14 of the upper portion 15 will preferably be slightly large, these two bores elng separated by the inwardly extending shoulder 16. Preferably the shoulder 16 will be positioned about midway the length of the head member l0 as shown.

Outlets 17 are provided in the lower neck portion 13, just above the screw threaded portion, into which pipes 18 may be connected for carrying the muck etc., to sump holes during the drilling operations. When not in use these openings may be plugged.

A tubing 19 is supported within and centrally of the casing 11 by means of a collar 20 screw threadedly connected to its upper end in an internally screw threaded bore 21. This bore is also screw threaded at its upper end for the connection therein of an upper tubing section 22. The collar 20 preferably has a reduced cylindrical portion 23 at its lower end which is adapted to have a close sliding fit within the bore 12, while its upper enc is of a diameter and size to have a comparatively close sliding fit within the bore or opening 14. Preferably the bore or opening in the upper section 15 will be slightly enlarged from a short distance above the shoulder 16 to facilitate in inserting the several different collars therein, it being desirable however that the portion of this bore or opening immediately adjacent the shoulders 16 have a close fitting with the collar 20.

A relatively soft sealing or packing material 211, such as lead or the like, is interposed between the shoulder 16 and a complementary inverted annular shoulder 25 upon the collar 20. Preferably the face of the shoulder 25 will be V-shaped, providing a comparatively sharp edged rib for biting y into the sealing member 24. However, this may be dispensed with if desired or it may also be formed on the shoulder 16. But inasmuch as it is desired that the shoulder 16 provide a right angular support for the collar and hence the tubing, the construction will be as shown.

While the weight of the tubing 19, carried by the collar 20, will, in itself, provide sufficient force to effect a good sealing between the collar 2O and head member 10, this is additionally accomplished by means of wedges 26 extending through apertures 27 in the upper head portion 15. After the collar 20 is set the wedges 26 are inserted through openings 27 and driven in until `the casing it may their lower beveled edges 28 securely clamp the collar 20 down upon the seat 16, with the packing 24 clamped therebetween. By this means the collar 20 is very easily and quickly set and may be as easily and quickly removed without the necessity 'of turning or unscrewing threads or without the use of wrenches or tongs.

In addition to the foregoing thisl partienlar type ot' casing head permits the use of other appliances tor other purposes during the drilling operation. For instance, when lowering the tubing 19 into the well a circular guide block 29 may be set into the head 1() and supported upon the shoulder 16, in the manner illustrated. Such a block will preferably be formed of brass or wood ,and split tluough its center so it may be placed around the tubing at any time. This has an annular shoulder 3() adapted to seat upon the shoulder 16 and it may extend below this shoulder or not, as desired. It has a concentric bore 3l through which the tubing 19 slidesso that the latter will be held and guided centrally within the casing 11. This guide block may also be held securely seated upon the shoulder 16 by use of the wedges 26, in the manner hereinafter described. Blocks such as these may be used for closing the top of the casing when the tubing extends thereabove and when it is desired to flush out the bore or to permit the passage of muck outwardly through the laterals 18.

In Fig. 4 I have illustrated how the head is used for supporting the tubing 19 within the easing when lowerino' it into the bore. In this case supporting blocks 32, of complementary semi-circular configuration have -shoulders 33 adapted to seat upon the shoulders 16. These may be temporarily retained in place by means of screws 34 extending through the walls of the upper head portion 14 or by the wedges 27. These merely retain the blocks 32 upon their seat when the tubing 19 is raised by the elevator 35. The blocks 32 have diametrically opposed slots 36 therein, and these have their rear faces 37 converging downwardly for the reception and holding of slips or wedges 38. These have serrated irllier `filces 9 to facilitate ori i ino` and ho ing t e tu infr 19 in sitiorriip When it is desired to lewe-,1` the tu ing into the casing it 'is raised slightly by the elevator 35 and the slips 38 removed after which it is lowered t0 the desired point and the slips again inserted.

Both of the devices shown in Figs. 3 and 4 have been generally known in the art before and I here show and describe them primarily for the purpose of showing the simplicity of their use with my improved typo of casing head.

When the tubin 19 is first lowered into guided by use of the guide blocks 29, as illustrated in Fig. 3. When it is desired to hold the tubing at any particular point, without the necessity of an elevator 35, the supporting blocks 32 and slips 38, as illustrated in Fig. 4 are utilized. After the tubing 19 has been lowered into the casing the required distance it is set and temporarily held, as illustrated in Fig. 4. The collar 39 is then removed and the collar 2O screwed on to it after which the short length of tubing 22 is screwed into the upper bore thereof. A collar is provided upon this length of tubing 22 so that tho elevator' may be attached-as shown in Fig. 4-and the whole is then lowered until the collar 2() seats upon the shoulder 16, as illustrated in Fig. 1; the packing 2() being first placed around the seat 16. After the collar 20 is thus seated the wed es 26 are then driven in place to complete t ie seating and sealing.

From the foregoing it is clear that I have provided an extremely simple and eflicient casing head which not only is adapted for sealing the upper end of the casing but also may be utilized in combinations with the def vices shown in Figs. 3 and 4 for both holding the tubing centered in the casing, during its upward or downward movement or holding the tubing suspended within the cas ing at any desired point.

Having described a preferred form of my invention, I claim:

A easing head, comprising a cylindrical head mem er adapted to be secured to the upper end of a casin said member having an enlarged bore at its upper end forming an annular, horizontally dis osed seat therein; a complementary, cylin rical plu" mem ber insertable in the head member, or supporting a tubing centrally of the casing, sald plug being adapted to fit closely in the upper, enlarged end of the head member and having a reduced lower end adapted to fit closely in the head below the annular seat, said reduced lower end forming a complementary, annular horizontally disposed shoulder on the plug to engage the seat; a relatively soft packmfr member interposed between the seat and s ioulder; apertures in opposite sides of the upper portion of the head member on each side of its center, said apertures being positioned to extend above and below the normal level of the top face of the plug; and wedge members adapted to extend through each pair of apertures and across the top of the plug on either side of its center, to removably secure the plug in place on the seat.

In witness that I claim the foregoing I have hereunto subscribed my name this 31st day of December 1924.

JOHN W. MCQUAID. 

